Hypercholesterolemia (literally: high blood cholesterol) is the presence of high levels of cholesterol in the blood . It is not a disease but a metabolic derangement that can be secondary to many diseases and can contribute to many forms of disease, most notably cardiovascular disease. It is closely related to the terms "hyperlipidemia" (elevated levels of lipids) and "hyperlipoproteinemia" (elevated levels of lipoproteins). Familial hypercholesterolemia is a rare genetic disorder that can occur in families, wherein those affected cannot properly metabolise cholesterol.